DESCRIPTION: This high risk/high impact proposal seeks to demonstrate a method of producing recombinant glycoproteins with defined carbohydrate patterns and high homogeneity by expression in Lec1 CHO cells. These cells lack a key enzyme, and they produce proteins homogeneously glycosylated with N-acetylglucosamine2-mannose5. The approach is to be demonstrated with Thy-1 a 111 amino acid, 3 N-linked glycosylated surface glycoprotein that inhibits the growth of CNS neurons. The pEE14 glutamine synthetase based vectors would be used to provide enough Thy-1 for structure determination. The long-term gaol is to determine the structure of Thy-1 to gain insights into cell growth regulation in the CNS by this family of inhibitory surface glycoproteins. The hope is to facilitate the development of agents to promote CNS regeneration.